Draft-indicator for vessels



(No Model.)

R. 0. PRINGLE.

DRAFT INDICATOR FOR VESSELS.

No. 467,996. Patented Feb. 2, 1892.

NITED STATES PATENT OFFICE.

ROBERT C. IRINGLE, OF MARINE CITY, MICHIGAN.

DRAFT-IN DICATOR FO R VESSELS.

SPECIFICATION forming part of Letters Patent No. 467,996, dated February 2, 1892.

Application filed October 13, 1890 Serial No. 368,049- (No model.)

To all whom it may concern.-

Be it known that I, ROBERT C. PRINGLE, a citizen. of the United States, residing at Marine City, in the county of St. Clair and State of Michigan, have invented a new and useful Vessel-Draft Indicator, of which the following is a specification.

My invention relates to indicators of an automatic nature, which will show at any and all times the depth of water a vessel is drawing. I attain this object by the mechanism illustrated in the accompanying drawings, in which- Figure 1 is a cross-section of a vessel, showing the arrangement of the device as connected with the sea-cock. Fig. 2 is a simpler form of an indicator. Fig. 3 shows the float and counter-balance with extra or compensating balances attached.

Similar letters refer to similar parts in all the views.

The want of some simple, accurate, and reliable device for indicating the depth of water a vessel is drawing while loading has long been a pressing want to the vesselanen of the Great Lakes on account of the shallowness of certain portions of those great water-ways which float a large portion of the worlds products. For this reason the draft of its large vessels is limited, and as every inch of its possibilities to float deeply-laden vessels is taken great lossis often entailed by grounding on account of the want of accurate means of knowing just when the greatest depth of draft allowable is reached in loading.

In my device I make use of the sea-cock inlet-pipes fore and aft, (as indicators must be placed at both ends of a vessel,) or, in fact, of any pipe piercing the side or bottom of the vessel below the light-draft line. To do this I extend the inlet portion a of the sea-cock into the indicator-well a, which may be ofwood or metal, round or square, and about four inches across. This well shouldbe brought up to the main deck and the connections to the indicator properly in closed. In this well, which necessarily holds an equal level of waterwith that outside, is a float Z), of any proper shape or material, a hollow metal sphere or wooden block, and to which is attached a sprocket-chain 0, either directly or by means of a wire (Z, leaving, however, more sprocketchain than the difference in feet between the minimum and maximum drafts of the vessel. This chain runs over the sprocket-wheel c, which is placed at least high enough to allow the chain to cause one revolution of the hand 72, while the other end is attached to a countor-balance f, which should be a little lighter than the combined weight of the float and that portion of the sprocket-chain between it and the top of the wheel when the vessel is in light draft. This weight should be properly boxed around to a bottom nearly as low down as the inlet-pipe, as shown in Fig.1. On the inlet-pipe, between the sea-cock and the indicator-well, is a valve to close the connection when the vessel is in motion or whenever desired. Attached to the sprocketwheel or centered on the same spindle is a small gear-wheel g, which sets in motion the larger one g, to which is attached the indi- Gator-hand h, which points to the proper figure indicating the draft on the circular or annular indicator-face d, fixed in the proper place for that purpose. It is only necessary that the figures should commence with the light-draft one, as shown on the face, Fig. 1. To illustrate proportions, if the sprocketwheel were two feet in circumference, the small gear-wheel one and one-half inches in diameter and the larger one six inches, and the vessels light draft three feet, then any draftup to eleven feet could be indicated by one revolution of the hand. The device may be made as light as clock-work; but as it may be deemed necessary in some cases to make it somewhat heavy and strong it might then require compensating balances Z Z, attached to both weight and float, as shown in Fig. 8, being small chains fastened to the bottom of each, so that when the major portion of the sprocket-chain comes on the counterbalance side, as when the vessel sinks deep into the water, an equal length of compensating chain Z is taken up by the float and a correspond ing portion of Z laid on the bottom on the other side, thus preventing the lifting of the float out of the water, which otherwise might happen. 7

A simpler form of the device and one that will answer just as well in many cases is shown in Fig. 2. In this form an ordinary tape-lino is attached to the float, running over an appropriate Wheel or revolving block j, with a A vessel-draft indicator composed ofa well counter-balance sufficient to keep it taut. connected 'with the water in which the vessel The depth of'cliaft can be readfi'om the figfloats, a float therein, a sprocket chain and ures of the tape-line, and thus dispense with wheel, a counter-balance, and compensating 15 the hand and indicator face, or a fine chain balances, all substantially as shown, and for might be used with small metal tags attached, the purposes specified.

showing feet and-quarters. i

The device is too simple to need further ex- ROBERL G planation. \Vitnesses: to What I claim, and desire to secure by Let- GEO. W; CARMAN,

ters Patent, is- FRANK S. PARKER. 

